RELATIONSHIP OF OIL PALM INFLORESCENCE AND EVALUATION OF SEVERAL INSECTICIDES ON Tirathaba mundella Walker (LEPIDOPTERA: PYRALIDAE) AND Elaeidobius kamerunicus Faust (COLEOPTERA: CURCULIONIDAE) MUHAMMAD IDRUS SHUKOR UNIVERSITI SAINS MALAYSIA 2017
RELATIONSHIP OF OIL PALM
INFLORESCENCE AND EVALUATION OF
SEVERAL INSECTICIDES ON Tirathaba mundella
Walker (LEPIDOPTERA: PYRALIDAE) AND
Elaeidobius kamerunicus Faust (COLEOPTERA:
CURCULIONIDAE)
MUHAMMAD IDRUS SHUKOR
UNIVERSITI SAINS MALAYSIA
2017
RELATIONSHIP OF OIL PALM
INFLORESCENCE AND EVALUATION OF
SEVERAL INSECTICIDES ON Tirathaba mundella
Walker (LEPIDOPTERA: PYRALIDAE) AND
Elaeidobius kamerunicus Faust (COLEOPTERA:
CURCULIONIDAE)
by
MUHAMMAD IDRUS SHUKOR
Thesis submitted in fulfilment of the requirements
for the Degree of
Master Science
July 2017
II
ACKNOWLEDGEMENT
My highest gratitude to ALLAH for giving me this opportunity to pursuit my
dream on becoming a post-graduate student. Praise to ALLAH for letting me complete
this project.
I would like to appreciate and honour my supervisor, Prof. Abu Hassan Ahmad
for giving all of his effort in helping me completing this thesis. Without his guidance,
I am sure this thesis will be a never ending task. A special thank you for my co-
supervisor, Dr. Abdul Hafiz Ab Majid for always keeping me up-to-date especially to
my study and my post-graduate time in general. Thank you so much to both of you.
An appreciation towards Mr. Aiman Hanis Jasmi and Mr. Siaw Ting Chuan
for giving me the opportunities to conduct my study in Ta Ann plantation. Thanks for
helping me out from Sibu to Mukah so that this study can be done successfully.
A special thanks I bid to Dr. Hasber Salim and Muhammad Farhan Ali for
helping me in giving advices, good discussions and exchange experiences throughout
my post-graduate time. It’s such a wondrous moments in meeting both of you.
I wish upon an eternal thank you and love to both my parents and family
members for their funding and moral support towards the whole processes of this
project. Their advices and ideas had helping me up in performing this project. Thank
you.
In deep gratitude, I thanks my friends, Nurul Najwa Abdul Mokti for
continuous support throughout the process in completing this thesis.
“So verily, with the hardship, there is relief”
Quran 94: 5
III
TABLE OF CONTENTS
ACKNOWLEDGEMENT II
TABLE OF CONTENTS III
LIST OF ABBREVIATIONS VII
LIST OF TABLES IX
LIST OF FIGURES XI
LIST OF PLATES XII
LIST OF APPENDICES XIV
ABSTRAK XV
ABSTRACT XVII
CHAPTER 1: INTRODUCTION 1
CHAPTER 2: LITERATURE REVIEW 4
2.1.1 Oil palm and their importance 4
2.1.2 Biology of oil palm 4
2.1.3 Oil palm inflorescence and bunch phenology 6
2.1.4 Acreage of oil palm planted in Malaysia 6
2.1.5 Oil palm planted on peat soil 8
2.1.6 Pollinators of oil palm 9
2.1.7 Predators and parasitoids of oil palm pests 11
2.1.8 Pests of oil palm 12
2.2.1 Tirathaba mundella 15
2.2.2 Biology of Tirathaba mundella 16
2.2.3 Identification of Tirathaba mundella 18
2.2.4 Population and distribution of Tirathaba mundella 19
IV
2.2.5 Control on Tirathaba mundella 20
2.3.1 Elaeidobius kamerunicus 21
2.3.2 Ecology and population of Elaeidobius kamerunicus 22
2.3.3 Importance of Elaeidobius kamerunicus 23
2.3.4 Issues related with the Elaeidobius kamerunicus 23
2.4.1 Insecticides 24
2.4.2 Insecticide properties and application used to treat Tirathaba
mundella
24
2.4.3 Insecticide efficacy and residual used to treat Tirathaba
mundella
26
2.4.4 Insecticide effect towards Elaeidobius kamerunicus 27
CHAPTER 3: RELATIONSHIP BETWEEN THE PHENOLOGY OF FEMALE
OIL PALM BUNCH AND Tirathaba mundella
29
3.1. Introduction 29
3.2. Material and Methods 30
3.2.1 Female oil palm bunch phenology 30
3.2.2 Tirathaba mundella symptoms and larval population
assessment between sites
34
3.2.3 Tirathaba mundella adult emergence rate from different bunch
phenology
42
3.3. Results 44
3.3.1 Female oil palm bunch phenology 44
3.3.2 Tirathaba mundella symptoms and larval population
assessment between sites
45
V
3.3.3 Correlation and regression between the female oil palm bunch
phenology and Tirathaba mundella symptoms
46
3.3.4 Tirathaba mundella adult emergence rate from different bunch
phenology
50
3.4. Discussion
51
CHAPTER 4: THE RELATIONSHIP OF MALE OIL PALM
INFLORESCENCE STAGES AND Elaeidobius kamerunicus
58
4.1. Introduction 58
4.2. Material and Method 59
4.2.1 Male oil palm inflorescence phenology at 3 different sites 59
4.2.2 The developmental time of oil palm male inflorescence 63
4.2.3 Elaeidobius kamerunicus adult population 67
4.3. Results 69
4.3.1 Male oil palm inflorescence phenology at 3 different sites 69
4.3.2 The developmental time of oil palm male inflorescence 70
4.3.3 Elaeidobius kamerunicus adult population 72
4.3.4 Correlation and regression between male inflorescence
phenology and Tirathaba mundella symptoms
73
4.4. Discussion 77
CHAPTER 5: FIELD EVALUATION OF SEVERAL INSECTICIDES
TOWARDS Tirathaba mundella POPULATION AND EFFECT
ON Elaeidobius kamerunicus POPULATION
81
5.1. Introduction 81
5.2. Material and Methods 82
VI
5.2.1 Trial 1: Efficacy of several insecticides towards Tirathaba
mundella population
83
5.2.2 Trial 2: Residual effect of several insecticides towards
Tirathaba mundella population
85
5.2.3 Trial 3: Effect of several insecticides towards the Elaeidobius
kamerunicus population
86
5.3. Results 88
5.3.1 Trial 1: Efficacy of several insecticides towards Tirathaba
mundella population
88
5.3.2 Trial 2: Residual effect of several insecticides towards
Tirathaba mundella population
92
5.3.3 Trial 3: Effect of several insecticides towards Elaeidobius
kamerunicus population
99
5.4. Discussion 102
CHAPTER 6: GENERAL SUMMARY AND CONCLUSION 108
LITERATURE CITED 112
APPENDICES 128
VII
LIST OF ABBREVIATIONS
A Floral part (spathe)
Ach Acetylcholine
AChE Acetylcholinesterase
B Female inflorescence pre-anthesis
BBCH Biologische Bundesantalt, Bundessortenamt und Chemische
Industrie
BD Banting dura
C Female inflorescence at-anthesis
CPO Crude palm oils
D Female inflorescence post-anthesis
DAA Day after application
DDT Dichlorodiphenyltrichloroethane
DxP Dura x Pisifera = Tenera
E Young bunch
EIL Economy injury level
ENH Young bunch with new frass and high infestation
ETL Economy threshold level
F Middle bunch
FFB fresh fruit bunch
G Old bunch
GABA Gamma-Aminobutyric acid (γ-Aminobutyric acid)
K Potassium
L Low infestation
VIII
M Medium infestation
N Nitrogen / New frass
nAChR Nicotinic acetylcholine receptor
O Old frass
P&D Pest and disease
RyRs Ryanodine
VGM Vegetative growth measurement
X No frass/ No infestation
IX
LIST OF TABLES
Page
Table 2.1: Acreage of oil palm planted in the different states of Malaysia 7
Table 2.2: Insect visitor on oil palm inflorescence 10
Table 2.3: Insect visitor on oil palm inflorescence 15
Table 2.4: Detail diagram of Tirathaba sp. life cycle done by Riana (2000) 18
Table 3.1: Location of sampling sites for oil palm bunch phenology 30
Table 3.2: Differences between female bunches according to their ages,
phenology and BBCH scale
32
Table 3.3: Preliminary result of Tirathaba larvae population count on
different bunch categories
42
Table 3.4: Mean number of female bunch stage per palm at TAPI1, TAPI2
and ZOP
44
Table 3.5: Comparison of Tirathaba mundella damage and larval
population assessment at three different sites
45
Table 3.6: The differences between the female oil palm bunch phenology
and Tirathaba mundella symptoms at TAPI1, TAPI2 and ZOP
46
Table 3.7: The correlation between female oil palm bunch phenology and
Tirathaba mundella symptoms
47
Table 3.8: Number of T. mundella moth adult emergence rate per bunch on
different bunch stages
50
Table 4.1: Location of sampling sites for male oil palm inflorescence
phenology
59
Table 4.2: Differences between male inflorescences according to their
ages, phenology and BBCH scale
61
X
Table 4.3: Male inflorescence phenology details including four
distinguished anthesizing stages
64
Table 4.4: Mean number of male inflorescence per palm at TAPI1, TAPI2
and ZOP
69
Table 4.5: Mean day taken for each male inflorescence stage ± standard
error at ZOP
70
Table 4.6: Mean number of pollinating weevil adult population at ZOP 72
Table 4.7: The differences between the male inflorescence phenology and
Tirathaba mundella symptoms
73
Table 4.8: The correlation between male oil palm bunch phenology and
Tirathaba mundella symptoms
74
Table 5.1: Location of trial sites for the field evaluation of several
insecticides towards Tirathaba mundella population and their
effect on Elaeidobius kamerunicus population
83
Table 5.2: Treatments and dosages of insecticides for each trial 83
Table 5.3: Bunches with new infestation from Tirathaba mundella after
being sprayed with insecticides
90
Table 5.4: Mean count of Tirathaba mundella larval population per bunch
after being sprayed with insecticides
90
Table 5.5: Bunches with new infestation of Tirathaba mundella after 70
days
94
Table 5.6: Mean count of Tirathaba mundella larvae per bunch after 70
days
95
Table 5.7: Mean count of alive Elaeidobius kamerunicus adult in one day
after application of insecticides
100
XI
LIST OF FIGURES
Page
Figure 2.1: Life cycle of Tirathaba sp. 17
Figure 3.1: Map detail for a replicate with 20 study palms 31
Figure 3.2: The linear regression line between Tirathaba mundella new infestation
with female middle and rotten bunch
48
Figure 3.3: The linear regression line between Tirathaba mundella larval population
with female middle and rotten bunch
49
Figure 4.1: Details for a replicate with 20 study palms 60
Figure 4.2: The developmental time of oil palm male inflorescence stage at ZOP,
Sibu, Sarawak
71
Figure 4.3: The linear regression line between Tirathaba mundella new infestation
with male pre-anthesis and post-anthesis inflorescence
75
Figure 4.4: The linear regression line between Tirathaba mundella larval population
with male post-anthesis inflorescence
76
Figure 5.1: Trial 1 overall result, A: Percentage reduction of T. mundella new
infestation, B: Percentage reduction of T. mundella larval population
91
Figure 5.2: Mean of new infestation and Tirathaba mundella larval count for Bt 96
Figure 5.3: Mean of new infestation and Tirathaba mundella larval count for
chlorantraniliprole
96
Figure 5.4: Mean of new infestation and Tirathaba mundella larval count for
fipronil
97
Figure 5.5: Mean of new infestation and Tirathaba mundella larval count for
cypermethrin
97
XII
Figure 5.6: Mean of new infestation and Tirathaba mundella larval count for
control
98
Figure 5.7: Percentage mortality of Elaeidobius kamerunicus on several insecticides
in 1 day
101
Figure 5.8: The relationship between Tirathaba mundella larval infestation and
application of insecticide
105
XIII
LIST OF PLATES
Page
Plate 3.1: Palm condition 31
Plate 3.2: Pictures of female inflorescences and bunches according to their stage,
phenology and BBCH scale on oil palm grown on peat soil
33
Plate 3.3: Tirathaba sp. frass condition on oil palm bunch 36
Plate 3.4: Tirathaba sp. infestation level on oil palm bunch 37
Plate 3.5: Description for Tirathaba sp. larval instar and size 38
Plate 3.6: The cutting procedure details 39
Plate 3.7: Example of young bunch with new frass and high infestation (ENH) 41
Plate 3.8: Female Tirathaba sp. whole specimen 43
Plate 3.9: Caged bunches for Tirathaba mundella adult emergence 43
Plate 3.10: Female pre-anthesis bunch with new and high infestation 53
Plate 3.11: ENH bunch condition after 2 months 54
Plate 3.12: Red circle indicating Tirathaba mundella damage on young fruitlet 57
Plate 4.1: Male oil palm inflorescences 62
Plate 4.2: Pictures of detailed male inflorescences phenology 65
Plate 4.3: Abnormal male oil palm inflorescences 66
Plate 4.4: Male inflorescence parts and process on collecting weevil 68
Plate 5.1: Spraying procedure 87
Plate 5.2: Bunch condition after treated with insecticide 106
XIV
LIST OF APPENDICES
Page
Appendix 1: Preliminary result of Tirathaba larval population count on
different bunch categories
128
Appendix 2: Statistical analysis for female and male oil palm bunch
phenology study
129
Appendix 3: Statistical analysis for Tirathaba mundella symptoms and
larval population assessment between sites
129
Appendix 4: Statistical analysis for Correlation and regression between the
oil palm bunch phenology and Tirathaba mundella symptoms
130
Appendix 5: Tirathaba sp. specimen of forewing and hindwing 132
Appendix 6: Statistical analysis for Trial 1: Efficacy of several
insecticides towards Tirathaba mundella population
133
Appendix 7: Statistical analysis for Trial 2: Residual effect of several
insecticides towards Tirathaba mundella population
135
Appendix 8: Statistical analysis for Trial 2: Residual effect of several
insecticides towards Tirathaba mundella population
(Tirathaba mundella larvae count)
137
Appendix 9: Statistical analysis for Trial 3: Effect of several insecticides
towards pollinating weevil population
139
XV
HUBUNGAN BUNGA KELAPA SAWIT DAN PENILAIAN BEBERAPA
JENIS RACUN SERANGGA TERHADAP Tirathaba mundella Walker
(LEPIDOPTERA: PYRALIDAE) DAN Elaeidobius kamerunicus Faust
(COLEOPTERA: CURCULIONIDAE)
ABSTRAK
Pokok kelapa sawit, (Elaies guineensis Jacq.) dari keluarga Palmae berasal dari
Afrika Barat dan telah dibawa masuk ke Malaysia oleh Kolonial British. Ia kini
dikenali sebagai "tanaman emas" dan telah menjadi salah satu daripada tumbuhan
penghasil minyak yang paling penting di dunia. Bunga dan tandan kelapa sawit adalah
diet penting kepada dua serangga, ulat pengorek buah, Tirathaba mundella Walker
dan kumbang pendebungaan, Elaeidobius kamerunicus. Faust Tirathaba.mundella
menyebabkan 50% kerosakan terhadap buah tandan segar (FFB) manakala E.
kamerunicus merupakan pendebunga penting. Objektif kajian ini ialah: (1) untuk
mencari hubungan antara peringkat bunga dan tandan kelapa sawit dengan T. mundella
dan E. kamerunicus, (2) untuk mencari keberkesanan dan sisa kesan daripada beberapa
racun serangga terhadap populasi T. mundella dan (3) untuk menentukan kesan
daripada beberapa racun serangga terhadap populasi E. kamerunicus. Dengan
menggunakan Biologische Bundesantalt, Bundessortenamt und Chemische Industrie
atau skala BBCH, peringkat bunga dan tandan kelapa sawit telah dijelaskan dan
digunakan untuk kajian lanjut mengenai kedua-dua serangga. Keputusan
menunjukkan bahawa tandan kecil (E) dengan frass baru (N) dan serangan tinggi (H)
mempunyai bilangan larva T. mundella yang tertinggi. Lokasi yang mempunyai
jumlah tandan busuk yang tinggi mempunyai serangan dan kiraan larva T. mundella
yang tinggi. Selain itu, lokasi dengan jumlah tandan busuk yang tinggi juga
mempunyai jumlah bunga jantan yang rendah. Kedua-dua keputusan menunjukkan
XVI
bahawa pendebungaan yang lebih rendah menyebabkan serangan T. mundella
meningkat sekali gus meningkatkan jumlah tandan busuk. Masa yang diambil untuk
bunga jantan untuk melengkapkan perkembangan adalah kira-kira 9 hari. Kajian
mendapati bahawa populasi kumbang pendebungaan adalah paling banyak pada masa
kemuncak pembungaan. Chlorantraniliprole mempunyai keberkesanan dan kesan sisa
yang tertinggi terhadap serangan baru dan kiraan larva T. mundella. Selain itu,
chlorantraniliprole juga mempunyai kesan yang sama seperti Bacillus thuringiensis
kurstaki (Bt) iaitu menyebabkan kesan yang paling rendah terhadap populasi dewasa
E. kamerunicus.
XVII
RELATIONSHIP OF OIL PALM INFLORESCENCE AND EVALUATION
OF SEVERAL INSECTICIDES ON Tirathaba mundella Walker
(LEPIDOPTERA: PYRALIDAE) AND Elaeidobius kamerunicus Faust
(COLEOPTERA: CURCULIONIDAE)
ABSTRACT
Oil palm plant, (Elaies guineensis Jacq.) from family Palmae was originated
from the West Africa and was brought into Malaysia by British Colony. It is now
known as the “golden crop” and have become one of the most important oil producing
plants in the world. Oil palm inflorescences and bunches are important diet for two
insects, the fruit bunch moth, Tirathaba mundella and the pollinating weevil,
Elaeidobius kamerunicus. T. mundella cause 50 % loses of fresh fruit bunch (FFB)
while E. kamerunicus is an important pollinator. The objectives of this study are: (1)
to find the relationship between the oil palm inflorescences and bunches stage with T.
mundella and E. kamerunicus, (2) to find the efficacy and residual effect of several
insecticides towards the T. mundella population and (3) to determine the effect of
several insecticides towards the E. kamerunicus population. By using Biologische
Bundesantalt, Bundessortenamt und Chemische Industrie or BBCH scale, the oil palm
inflorescences and bunches stage were described and used for further study on both
insects. The results show that the young bunch (E) with new frass (N) and high
infestation (H) have the highest count of larvae. Location with high rotten bunches are
having high T. mundella infestation and larvae count. Besides, location with high
rotten bunches also had low male inflorescence. Both results show that lower
pollination which caused T. mundella infestation to increase thus increasing the rotten
bunches count. The time taken for male inflorescence to complete their development
was approximately 9 days. The study found that pollinating weevil populations were
most abundant during peak anthesis time. Chlorantraniliprole had the highest efficacy
XVIII
and residual effect towards T. mundella new infestation and larvae count. Beside,
chlorantraniliprole also had similar effect as Bacillus thuringiensis kurstaki (Bt) which
caused the least detrimental effect towards E. kamerunicus adult populations.
1
CHAPTER 1: INTRODUCTION
Elaeis guineensis (Palmae: Arecaceae) was originated from the West Africa
and was brought into Malaysia by British Colony. It is now known as the “golden
crop” and have become one of the most important oil producing plants in the world.
One hectare of oil palm plantation is able to produce 10 times more oil than other
oilseed crops (Abdullah, 2011). Its optimal production period are between 10- 15 years
and it can last long up to 20 years. Oil palm seeds were converted into refined palm
oil through many process like hydrolysis and oxidation. The liquid fraction, oil palm
olein is commonly used as cooking oil in the tropical regions compared to other oils
like groundnut and sunflower (Kusum et al., 2011).
The importance of palm oil caused the peat soil to be converted into oil palm
plantation. Oil palm cultivated on peat was estimated at 666 038 ha (13 %) (Wahid et
al., 2010). Oil palms on peat were already in their 3rd generation (MPOB, 2012). Peat
soil or Histosols is the soil that are made up with more than 50cm depth of organic
matter. It is originated from swamp, bog or river that had been accumulated with
organic matter.
In Malaysia, oil palm is effectively pollinated by an introduced weevil,
Elaeidobius kamerunicus Faust (Coleoptera: Curculionidae) (Syed et al., 1982). Good
pollination required 15 to 30 weevils per inflorescence and 4000 to 30000 weevils per
hectare depending on male anthesis stage (Wahid and Kamarudin, 1997). The
fluctuation of weevil populations increased during dry season, however pollinating
efficiency is not affected because wind and other insects also play the role in
pollinating the inflorescence (Wahid and Kamarudin, 1997). Introduction of
pollinating weevil in 1981 had increased the fresh fruit bunch (FFB) of oil palm up to
2
30 %. Increasing in FFB can be obstructed by the pest that infested the oil palm such
as Tirathaba mundella, leaf eating caterpillar and rhinoceros beetle.
One of the most important pests affecting the FFB quantity and quality is
Tirathaba mundella (Lepidoptera: Pyralidae). It is known as the fruit bunch moth or
inflorescence moth. Presently, this pest was reported to cause serious problem on oil
palms planted on peat soil (Lim et al, 2012). Their life cycle is about 1 month. The
damage symptoms are indicated by the presence of faeces or frass on the fruit or
inflorescences (Wood & Ng, 1974). Other symptoms that occur once the infestation
become worst are the premature abortion of the oil palm fruit, delayed spathes opening
and yellowing of spadices of the oil palm inflorescences (Lim, 2012). T. mundella
damaging symptoms and level of infestation is established through the monitoring
method and the routine sampling of FFB grading (Lim et al., 2012). Cultural control
method is usually done before the infestation occurred. Conducting biological control
measures will avoid destroying beneficial pollinators such as pollinating weevil and
thrip.
Recent study showed that broad spectrum chemical insecticide, cypermethrin,
also kill the oil palm pollinator, Elaeidobius kamerunicus and the fruit bunch moth
natural enemies, earwig. On the other hand, study has shown that Bacillus
thuringiensis (Bt) variety Kurstaki produced the best performance against fruit bunch
moth (Lim, 2012). The problems arise about Bt is that it does not have long shelf life
and lifespan, it need certified individual to operate and besides it does not last long in
the field condition. So this research will evaluate and select the best insecticide against
Tirathaba mundella under lab and field condition.
3
The overall objectives of this study are (1) to determine the relationship
between the female oil palm bunch phenology with the Tirathaba mundella new
infestation and larvae count, (2) to determine the relationship between the male oil
palm inflorescence phenology with the Elaeidobius kamerunicus adult count, (3) to
evaluate the insecticides that have the best efficacy and residual effect towards the T.
mundella population and caused the least detrimental effect towards the E.
kamerunicus population.
4
CHAPTER 2: LITERATURE REVIEW
2.1.1 Oil palm and their importance
The first commercial scale planting of oil palm in Malaysia was founded in
1917, the Tennamaran Estate in Selangor (Jagoe, 1952; Basiron, 2007). It is now
known as the “golden crop” and have become one of the most important oil producing
plants in the world and grown in 16 countries across tropic region (Wahid et al., 2005).
Nowadays, the world has increased their demand towards the palm oil. Fresh
fruit bunch (FFB) contain 25 % of oil and 5 % of kernel. Oil palm seeds are converted
into refined palm oil through many process like hydrolysis and oxidation. Indonesia
and Malaysia are the main world’s palm oil producers while the other countries include
Thailand, Columbia and Nigeria. Palm oil is used in a wide variety of food products
such as cooking oil, shortenings and margarine. Palm kernel oil is a raw material used
in the production of non-food products which include soaps, detergents, toiletries,
cosmetics and candles. Palm oil is increasingly being used as biofuel although its
primary use remains for food (Basiron, 2007).
2.1.2 Biology of oil palm
Oil palm is a monoecious plant, having both male and female on one palm. It
has pinnate leaf and is considered the best producer of oil in the world. The vegetative
components of a mature palm are the roots, trunk or stem and foliage (Turner and
Gillbanks, 2003). The palm bunch comprises of compacted fruitlets that weigh from
10 to 25 kg with 1000 to 3000 of fruitlets. Their fruitlet shape is mostly spherical or
elongated. Fruitlets are purple black when unripe and turned to orange black when ripe
(Corley and Tinker, 2003). The fruitlets consist of soft outer mesocarp, the shell
endocarp and the hard inner kernel (seed). Oil palm can grow more than 10 meter and
5
replanting is done when it reaches 20 to 25 years old (Corley and Tinker, 2003; Legros
et al., 2009). Oil palm growth and production depended on the vegetative dry matter
production because of the conversion of carbon into oil (bunch) required vegetative
parts that have efficient photosynthesis such as leaves (Corley, 1973).
After years of generation selection during 1920s, Deli dura rise in Malaysia
and Indonesia as it have heritable characters. Further breeding and selection give rise
to more variety population such as Elmina (E), Dumpy E206, Banting dura (BD),
Johore Labis dura (JLD) and Ulu Remis dura (URD) (Din, 2009).
Tenera/Pisifera was introduced into Malaysia in 1957 by Harrison &
Crossfield (now Sime Darby) and Department of Agricultural (DOA) of Peninsular
Malaysia. Tenera variety was obtained by combining both dura and pisifera which is
known as Yangambi population. After that, through breeding and selection, it evolved
into AVROS pisifera. La Me population obtained from developing oil palm plant
material from palm groves
Oil palm phenology or stage scale was well described from previous study by
Hormaza et al. (2012) using the BBCH scale (Biologische Bundesantalt,
Bundessortenamt und Chemische Industrie) as the references. BBCH scale was
established by Zadoks et al. (1974) to standardise the growth of plants by giving a
decimal number for each specific growth stage. Under BBCH scale, oil palm has three
growth stages comprised of germination and emergence (stage 0), leaf development
(stage 1) and stem elongation (stage 3) while reproductive growth comprised of four
stages: inflorescence emergence (stage 5), flowering (stage 6), fruit growth (stage 7)
and fruit ripening (stage 8). Last phenology is leaf senescence (stage 9). Total time
6
taken from inflorescence emergence to fruit ripening is around 519 days, the longest
period is during inflorescence emergence (Forero et al., 2012).
2.1.3 Oil palm inflorescence and bunch phenology
Forero et al. (2012) stated that inflorescence sexes were unable to be identified
during principle stage 5 because during this stage the prophyll and peduncular bract
were still covered the inflorescence completely. Once the inflorescence reached 90 %
of its final size (stage 509), the prophyll is torned apart completely while the
peduncular bract had a slight torn, during this stage, the inflorescence sexes can be
determined.
Both male and female inflorescences undergo principle stage 6: flowering.
Both of them have the same stages which are: pre-anthesis I (stage 601), pre-anthesis
II (stage 602), pre-anthesis III (stage 603), at-anthesis (stage 607) and post-anthesis
(stage 609). All the stages were differentiated based on the characteristic of peduncular
bract that disintegrate through all these processes.
Cik Mohd Rizuan et al., (2013) stated briefly that male inflorescence at-
anthesis can be differentiated into 4 distinct stages of ¼, ½, ¾ and full at-anthesis.
Further study on this matter is important because of the close relationship between the
at-anthesis male inflorescence and the pollinators of oil palm specifically the
pollinating weevil, E. kamerunicus.
2.1.4 Acreage of oil palm planted in Malaysia
Nowadays, Malaysia and Indonesia are producing 85% of world oil palm in
2016 (USDA-FAS, 2016). Peninsular Malaysia has about 2 million hectares of oil
palm plantation and East Malaysia (Sabah and Sarawak) comprised of 1.7 million
7
hectares thus making a total of 3.7 million hectares of oil palm cultivation. Table 2.1
shows the acreage of oil palm planted in the different states in Malaysia.
Table 2.1: Acreage of oil palm planted in the different states of Malaysia
State 1980 1990 1995 2000
Ha (%) Ha (%) Ha (%) Ha (%)
Johor 288,883 (27.0) 532,866 (26.3) 587,686 (23.1) 634,716 (18.8)
Kedah 11,211 (1.1) 29,296 (1.4) 37,166 (1.5) 57,375 (1.7)
Kelantan 18,238 (1.7) 60,490 (3.0) 70,834 (2.8) 72,065 (2.1)
Melaka 12,184 (1.1) 26,856 (1.3) 36,278 (1.4) 43,859 (1.3)
N. Sembilan 49,337 (4.6) 86,523 (4.3) 103,887 (4.1) 123,343 (3.7)
Pahang 276,464 (25.8) 439,663 (21.7) 498,417 (19.6) 514,709 (15.2)
P. Pinang 8,116 (0.8) 14,149 (0.7) 15,174 (0.6) 14,665 (0.5)
Perak 122,610 (11.5) 236,385 (11.6) 265,427 (10.5) 303,533 (9.0)
Selangor 100,875 (9.4) 149,489 (7.4) 148,242 (5.8) 1,325,467 (4.0)
Terengganu 67,589 (6.3) 122,781 (6.0) 140,060 (5.5) 145,767 (4.3)
P. Malaysia 955,507 (89.3) 1,698,498 (83.7) 1,903,171 (74.9) 2,045,500 (60.6)
Sabah 90,000 (8.4) 276,171 (13.6) 518,133 (20.4) 1,000,777 (29.6)
Sarawak 24,000 (2.3) 54,795 (2.7) 118,783 (4.7) 330,387 (9.8)
E. Malaysia 114,000 (10.7) 330,966 (16.3) 636,916 (25.1) 1,331,164 (39.4)
MALAYSIA 1,069,507 (100.0) 2,029,464 (100.0) 2,540,087 (100.0) 3,376,664 (100.0)
Source: Teoh, 2000; PORLA
Fertile soil in the coastal areas is suitable to grow oil palm in Peninsular
Malaysia. In Sabah, majority of oil palm plantations were from forest land or
converted crop land especially from cocoa. In Sarawak, the oil palms are planted
mostly on hilly areas of Bintulu division. There were 2.5 million of hectares that were
suitable for agricultural purposes with the areas mainly from hill, steep terrain or peat
swamps. From that total, 1.5 million hectares was under peat soil with 89% was
accounted as deep peat (Hai et al., 2001).
Manuring of oil palm generally depend on the type of soil where they are
planted. Goh (2005) stated that oil palm planted on clay soil need the least amount of
ammonium sulphate (1.59 kg/palm/year) and rock phosphate (1.14 kg/palm/year)
whereas the oil palm planted on sandy loam, silty clay, organic clay, shallow peat and
8
deep peat need literally large amount of ammonium sulphate (2.73 kg/palm/year) and
rock phosphate (1.82 kg/palm/year). Apart from that, both clay soil and deep peat need
high amount of potassium (3.64 kg/palm/year). Nutrient fixation and release in soil
are basically associated with the soil pH so maintaining soil pH between 3.5 to 5.5 pH
is crucial for the oil palm plant in order to get the best FFB yield (Goh, 2005; Lim et
al., 2012).
2.1.5 Oil palm planted on peat soil
Increasing demands and shortage of mineral land for oil palm plantation have
been overcome by converting peat land for oil palm plantation and nearly 25% of all
oil palm plantations right now are cultivated on peatlands (Sheil et al., 2009; Tan et
al., 2009). Peat soil or Histosols is the soil that are made up with more than 50cm depth
of organic matter. The peat soil condition occurred when the deposition of organic
matter is more than the decomposition process. The soil always low in pH as such it
is acidic in nature. The soil contained water log that can last for 3 month if a long
drought had occurred (Lim et al., 2012). The decomposing rate is reduced because of
the high water level that prevent aerobic decomposition of the plant materials
(Andriesse, 1988).
In term of pests, both peat and mineral soils have the same set of pests but on
peat, the pest’s infestation occurred earlier and outbreak became more frequently (Lim
et al, 2012). Mutert & Fairhurst (1999) predicted that oil palm grow on peat soil can
produce higher yield compared to palms grow on the mineral soil. The FFB yield can
produce up to 25.6 tonnes of crude palm oils (CPO), 6 tonnes higher than the mineral
soil.
9
Oil palm is grown by monoculture practice, and is known as monoculture crop.
Extensive monoculture have developed more pests, weeds and diseases to exploit
these unnatural environment of the monoculture: single crops, higher nutrient uptake
and mostly genetically the same (Altieri and Nicholls, 2005). This problem can be
solved by repairing and restoring community homeostasis through addition or
enhancement of biodiversity (Altieri and Nicholls, 2005). One of the well-known
process to repair the community homeostasis is the introduction of the beneficial
insects. Beneficial insects are differentiated into some roles that benefit to nature and
human (Van Huis et al., 2013). Benefits to nature are differentiated into several roles
such as pollinators (bees), predators (rove beetles), parasitoids (parasitic wasps) and
waste biodegradation (dung beetles) (Pickett, 1998) while benefit to human are
differentiated into valuable products (honey from bees), medicals (propolis from
bees), technology and engineering (silk thread from silk worm and termite hills).
Predators, parasitoids and pathogens are grouped under natural enemies of pests
(Howard et al., 2002). In term of oil palm industry, only pests, pollinators, predators
and parasitoids are importance to state.
2.1.6 Pollinators of Oil Palm
Pollinators are insects that assist in pollination of plant reproductive organs.
Pollination can be differentiated into 2: biotic (insects) or abiotic (wind) (Pellmyr et
al., 1991). Most plant reproductive organs were designed to closely associate with the
insects: having colourful petals, odour, sticky pollen and produce honey (Harborne,
1993). In oil palm pollination, a recent study shown that there are around 15 insects
that visit on oil palm inflorescence. Apart from that, only 4 species of insects that visit
both male and female inflorescences which are pollinating weevil, earwig, honeybee
10
and moth (Sambathkumar and Ranjith, 2013). List of insect visitors on oil palm
inflorescence is shown on Table 2.2.
Pollinating weevil was the most predominant and the best mechanism in
pollinating the oil palm inflorescences (Sambathkumar and Ranjith, 2013). Wind also
play a role in pollination with the ability to carry pollen up to 30 meters (Tandon et
al., 2001). In Malaysia, oil palm is effectively pollinated by pollinating weevil,
Elaeidobius kamerunicus Faust (Coleoptera: Curculionidae). It was introduced in
1981 (Syed et al., 1982) from West Africa and South America (Howard et al., 2002).
Table 2.2: Insect visitor on oil palm inflorescence
No. Insect Order: Family Visit on
inflorescence
Male Female
1 African oil palm weevil
(Elaeidobius
kamerunicus)
Coleopteran: Curculionidae Yes Yes
2 Earwig Dermaptera: Forficulidae Yes Yes
3 Moth Lepidoptera:
Cosmopterigidae
Yes Yes
4 Leaf caterpillar
(Elymnias sp.)
Lepidoptera: Nymphalidae Yes No
5 Citrus butterfly
(Papilio sp.)
Lepidoptera: Papilionidae Yes No
6 Butterfly – yellow
(Eurema hecabe)
Lepidoptera: Pieridae Yes No
7 Indian honey bee
(Apis cerana indica)
Hymenoptera: Apidae Yes Yes
8 Dammer bee
Trigona iridipennis)
Hymenoptera: Meliponidae Yes No
9 Black ant
(Camponotus sp.)
Hymenoptera: Formicidae No Yes
10 Leaf cutter bee
(Megachile sp.)
Hymenoptera: Megachilidae Yes No
11 Cuckoo wasp Hymenoptera: Chrysididae Yes No
12 Carpenter bee
(Xylocopa sp.)
Hymenoptera: Xylocopidae Yes No
13 Giant hornet
(Vespa sp.)
Hymenoptera: Vespidae Yes No
14 Mealy bug Hemipteran: Pseudococcidae No Yes
11
(Paracoccus marginatus)
15 Hover fly Diptera: Syrphidae Yes No
Source: Sambathkumar and Ranjith, 2013
2.1.7 Predators and parasitoids of oil palm pests
Predators regulate ecosystem by feeding on many preys. Some predators are
considered as stenophagous and another one as polyphagous. There was no evidence
on monophagous predators (Petráková et al., 2015). Stenophagous predators are
considered to consume a few closely related prey like spiders of the Ammoxenidae
family that preys specifically on termite (Pekár and Toft, 2015). Whereas polyphagous
predators are consuming a range of preys like rove beetle preys on vast range of
arthropods and plants (Weisser et al., 1999).
In oil palm, there are several types of predators that feed on the pests of oil
palm. Predators are found mostly from Coleoptera (Staphylinidae, Carabidae and
Coccinellidae), Neuroptera (Chrysophidae), Diptera (Syrphidae) and Heteroptera
(Pentatomidae and Miridae) (Howard et al., 2002). Ants like Oecophylla smaragdina
was said can be a control agent against Tirathaba sp. (Lim, 2012). Sycanus
dichotomus, Cosmolestes picticeps and Callimerus arcufer were said to prey on
lepidopteran larvae like Setora nitens, Pteroma pedula and Sethotosea asigna
(Kamarudin & Wahid, 2010; Jamian et al., 2015).
Parasitoids are the insects that their larvae feed on or inside the arthropod host,
which killed the host in the process. Parasitoids comprised nearly 600,000 species
worldwide (Heraty, 2009). Mostly parasitoids were from Orders of Hymenoptera,
Diptera, Strepsiptera and Lepidoptera. Parasitoids can be classified as ectoparasitoids
and endoparasitoids. Ectoparasitoid larvae developed outside the host body while
endoparasite the another way around (Howard et al., 2002). Endoparasite wasp also
12
oviposit other component like venom fluid alongside the egg to facilitate their progeny
development (Werren et al., 2010; Asgari and Rivers, 2011). Solitary parasitoids lay
single egg per host while gregarious parasitoids lay many. They were some events like
superparatism and multiparasitism that refer to a host was being parasitized by
multiple parasitoids from the same or different species.
There are many parasitoids that parasitized the pest of oil palm. Spinaria
spinator, Apanteles aluella, Systropus roepkei and Brachimeria lasus had been proved
to be an effective parasitoid to lepidopteran especially nettle caterpillar such as Setora
nitens and Sethothosea asigna. The braconid, Apanteles tirathabae parasitizes young
Tirathaba sp. larvae (Hinckley, 1964).
2.1.8 Pests of oil palm
Oil palm has many pests (insects and mammals) (Howard et al., 2002). Pests
are classified: (1) key pests are perennial pests that can cause severe damage and
having inadequate natural enemies, (2) occasional pests can cause sporadic economic
damage if their biological control have been disrupted and (3) induced or potential
pests can cause potential damage if environmental control are disrupted by change in
agricultural practice. Important pests are differentiated into 2 categories: vertebrate
and invertebrate (Turner and Gillbanks, 2003).
Important pests of oil palm are Tirathaba mundella, termite, leaf eating
caterpillar, rat and rhinoceros beetle (Lim et al., 2012). T. mundella is fruit borer. Their
life cycle is about 1 month. Adult lay eggs upon the damaged inflorescence, after about
5 days later, the emerging caterpillar bore into the spadices of the inflorescence.
Highly infested bunch will rot before reaching the ripening stage (premature abortive)
(Turner and Gillbanks, 2003; Lim et al., 2012). The larvae has 5 instars and will
continue eating for about 2 weeks. T. mundella late instar is brownish black in colour
13
and soon turn into pupae at bunch surface for about a week. Heavy infestation of T.
mundella reduce the production of fresh fruit bunch (FFB) by more than 50 % (Lim,
2012). Usages of bio pesticide Bt, Bacillus thuringiensis have been reported to show
remarkable result than endosulfan in suppressing these pests (Lim, 2012).
There is one species of termite that attacks living oil palm plants, especially
when planted on peat soils. It is known as Coptotermes sp. which attacks oil palm
plants as early as seven to eight month old. It causes three to five percent of death on
the immature oil palm plants. In mature palms (10 years old), it can cause more than
50 % death if no proper management was taken. The recommended chemical for
termite control is fipronil (5.0 % a.i.) at 2.5 ml product per 5 liters of water (Lim et al.,
2012).
Leaf eating caterpillar such as bagworm, nettle caterpillar and hairy caterpillar
can cause outbreak when the condition is favourable. They are known as defoliators.
Their population is usually stabilized by parasitoids such as Spinaria spinator. Crop
can losses 50 % of foliage at 30 to 40 % infestation rate in eight years oil palms.
Chemical control for young palms (1 – 6 years) is by spraying 0.005% cypermethrin
at fortnightly intervals on the infested canopy until new infestations clear off. When
mist-blowers are used, the concentration is increased to 0.01 %. Biological control can
be done by increasing the beneficial plants associate with parasitoids (Ariffin and
Basri, 2000).
Rats are important vertebrate pests in oil palm plantations on peat. They cause
damage in both mature and immature plantings. On mature palms, rats feed on loose
fruits and developing fruit bunches (Turner and Gillbanks, 2003). They also attack the
inflorescences. Crop losses due to rat damage were estimated at 7-10% if not properly
14
controlled. Rats can be control by using toxic baits and barn owl, Tyto alba (Lim et
al., 2012).
The rhinoceros beetle (Oryctes rhinoceros) is an important insect pest of
immature oil palms on peat. It is known as trunk borer. The beetles breed in rotting
woody materials, in trunks of oil palm in the field at the time of felling (Turner and
Gillbanks, 2003). In the Riau, Indonesia, rhinoceros beetles in peat areas often
migrated from the nearby coconut plantations (Lim et al., 2012). If control measures
are not applied quickly on immature palms, repeated attacks will lead to palm death,
arising from direct damage to the meristematic tissue. Monthly census is important for
newly planted palms in areas with high rhinoceros beetle population. On mature
palms, severe attacks will result in reduction of leaf area and subsequently lead to
pronounce male cycle and lower yields.
Table 2.3 shows the economy threshold level (ETL) of several known pests
that are associated with the oil palm.
15
Table 2.3: Economic threshold of important pests of oil palm
No. Common name
(infested part)
Scientific name Economic threshold Reference
1 Bagworm
(leaves)
Metisa plana
Pteroma pendula
Metisa plana
Mahasena corbetti
10 larvae/frond
30-60 larvae/frond
8-47 larvae/frond
5 larvae/frond
Wood (1971)
IRHO (1991)
Basri (1993)
Wood (1971)
2 Nettle caterpillar
(leaves)
Darna trima
Setora nitens
Darna diducta
Setothosea asigna
10 larvae/frond
30-60 larvae/frond
5-10 larvae/frond
10-20 larvae/frond
5 larvae/frond
Wood (1971)
IRHO (1991)
IRHO (1991)
IRHO (1991)
Hoong and Hoh
(1992)
3 Rhinoceros beetle
(crown/ leaves)
Oryctes rhinoceros 10% palms with
damage
3-5 adults/Ha (traps)
Wood (1968)
IRHO (1991)
4 Bunch moth
(inflorescence/bunch)
Tirathaba rufivena 30% of the palms with
at least one bunch
>50% attacked in
young plantings and
60% in older plantings
IRHO (1991)
5 Cockchafer Adoretus
Apogonia
5-10 adults/palm
10-20 adults/palm
IRHO (1991)
IRHO (1991)
6 Rat
(bunch)
Rattus spp. < 20% bait acceptance
5% bunch with damage
Wood (1968)
Basri & Norman
(2000)
Source: Ariffin & Basri (2000)
2.2.1 Tirathaba mundella
Nowadays, Tirathaba mundella, the fruit bunch moth has become widespread
and increasingly severe in both Malaysia and Indonesia (Turner and Gillbanks, 2003).
Short life cycle and peat soil condition are conducive to T. mundella population which
reduced the oil palm yield by more than 50% if no proper management and control are
taken (Lim et al., 2012). Adult lay eggs upon the damaged inflorescence and five days
later, the emerging caterpillar will then bore into spadices of the inflorescence. T.
mundella have five instars and will continue eating for about 2 weeks. The caterpillar’s
late instar is brownish black in colour and soon will form pupae for about a week.
16
They usually pupate at bunch surface. The pupae stay in cocoons of silken thread and
then emerge as adults. Both sexes of adults have wings and some reports said they are
practically sexual dimorphism (Chan et al., 1973). Worst affected palms usually
occurred in newly planting area, but older planting can also be badly infested and more
difficult to treat (Turner and Gillbanks, 2003).
2.2.2 Biology of Tirathaba mundella
Based on previous studies, female adult Tirathaba mundella can lay eggs from
30 to 50 eggs within three days (Riana, 2000). Female lay white eggs at the fibrous
sheath of the flower spike. Through time, the eggs will turn yellow, orange and black
when it hatched (Howard et al., 2002). All 5 stages of the larvae took between 14 to
19 days to complete and the total life cycle of T. mundella is between 26 to 34 days.
Figure 1 shows the life cycle of Tirathaba sp. (Riana, 2000). Table 2.4 explains the
detail of the life cycle of T. mundella (Riana, 2000).
Pupae is enclosed in a silken thread and takes 10 to 14 days before reaching
adult stage (Chan et al., 1973). Adults are practically different between genders, as
male moths have smaller size wings, visible male genitalia part and thinner abdomen
than female moths (Riana, 2000).
Peak activity of Tirathaba mundella adult male for mating is at 12 a.m.
(Sasaerila et al., 2002) and the extracted pheromone from these males has a compound
that resemble vanillin (Sasaerila et al., 2003). Unlike other lepidopteran that can be
caught on light trap, T. mundella moths were not flying towards light (Paine, 1994).
17
Figure 2.1: Life cycle of T. mundella (Riana, 2000)
18
Table 2.4: Detail diagram of Tirathaba mundella life cycle done by Riana (2000)
Stage Morphology Activity Development
period
(day)
Measurement
(mm)
Colour Shape
Egg 0.50 – 1.00 White at first
and orange
during hatched
Round
and scale
- 3 – 4
Larvae
Instar 1
Instar 2
Instar 3
Instar 4
Instar 5
1.00 – 2.00
5.00 – 6.00
9.00 – 10.00
16.00 – 18.00
12.00 – 15.00
Brownish white
Brown
Brownish black
Blackish brown
Blackish brown
dorsal with
greyish brown
ventral
Hairless
cruciform
Hairy
cruciform
Hairy
cruciform
Hairy
cruciform
Hairy
cruciform
Does not
eat
Eat
Eat
Eat
Does not
eat
3 – 4
4 – 5
2 – 5
4 – 5
1
Pupae 10.00 – 12.00 Brown Obtect - 7 – 8
Adult
Male
Female
11.00 – 12.00
14.00 – 15.00
Blackish brown
dorsal with
greyish brown
ventral
Blackish brown
dorsal with
greyish brown
ventral and
orange striped
abdomen
Triangular
shape,
slim
abdomen,
scale
wings
Triangular
shape,
broad
abdomen,
scale
wings
Nocturnal
Nocturnal
3 – 4
3 – 4
2.2.3 Identification of Tirathaba mundella
Tirathaba mundella (order Lepidoptera; family Pyralidae) are one of the most
diverse species worldwide (Mutanen et al., 2010). Pyralidae can be differentiated from
Crambidae by their forewing veins, sclerotized costad, bullae tympani and uncus arm
of male genitalia (Regier et al., 2013). Subfamily Gallerinae is described as lack of
19
gnathos (Munroe 1972; Arenberger et al., 2001), dorsum of thorax and abdomen with
prominent median ridge (Solis, 2007). There were several pests under this subfamily
included T. mundella, rice moth, Corcyra cephalonica and worldwide stored product
pest, Paralipsa sp. Under the genus Tirathaba, Hampson (1917) has stated 17 species
which are T. acrocausta, T. trichogramma, T. complexa, T. irrufatella, T.
pseudocomplana, T. mundella, T. ignivena, T. rufivena, T. maculifera, T. fuscistriata,
T. purpurella, T. grandinotella, T. semifoedalis, T. parasitica, T. haematella, T.
unicolorella and T. nitidalis.
Only two species of Tirathaba has been recorded responsible for infestation of
oil palm in Malaysia and Indonesia; T. mundella and T.rufivena. Susanto (2011)
differentiated these two species through their forewing coloration, where by T.
mundella is greenish and T. rufivena is greyish. However, Mariau (2001) has stated
that T. rufivena is the same species to T. mundella, T. fructivora, T. complexa and
Mucialla rufivena. Turner and Gillbanks (2003) combined both species together as
fruit bunch moth. Molecular technique done by Yaakop and Manaf (2015) showed
that T. rufivena and T. mundella are different species.
Other important Tirathaba species are T. trichogramma which is associated
with the premature nut-fall in Fiji (Hinckley, 1964) and T. complexa that is known as
Greater coconut spike moth (Godfray, 1985).
2.2.4 Population and distribution of Tirathaba mundella
Plants from the family Palmae are considered as the host for Tirathaba
mundella population. T. rufivena and T. mundella were considered as pests for
coconut, areca nut and oil palm (Corbett, 1931; Wood & Ng, 1974; Gallego and Abad,
1985; Basri et al., 1994; Huang et al., 2008; Lim, 2012). Tirathaba incidence were
20
reported in India, Philippines, Malaysia and Indonesia. T. mundella is infesting oil
palm plantation in Indonesia and Sarawak, Malaysia (Lim et al., 2012). T. mundella
incidences were recorded in various FELDA plantations especially in immature areas
located in Johor, Negeri Sembilan, Selangor and Perak (Wood and Ng, 1974).
2.2.5 Control on Tirathaba mundella
Samples of 20 bunches per 100 acres are proven to give a reasonable and
producible guide to the actual state of infestation. The economic threshold (ET) of
Tirathaba mundella infestation on oil palm is 3-5 larvae per fruit bunch (Wood & Ng,
1974). Young oil palm usually had heavier infestation because of their more
compacted crown and their inflorescences tends to remain within the sheath than
matured palm (Howard et al., 2002).
Cultural control method is usually carried out before the infestation occurred.
All the ripened, rotten and unproductive (ablated) fruits are harvested and kept away
from the plantation as this method has decrease the Tirathaba mundella population
(Wahid et al., 1991).
Biological control is about using predators, parasitoids or pathogens to control
pests (Ponnamma, 2001). Tirathaba mundella may be regulated by natural predators,
especially earwigs, Chelisoches moris and Kerengga ants, Oecophylla smaragdina
(Lim et al., 2012). The braconid, Apanteles tirathabae is a host specific parasitoid that
only parasitized young larvae of T. mundella (Corbett, 1930). This braconid may in
turn be parasitized by any of four hyperparasitoids: Aphanogmus manilae
(Ceraphronidae), Irichohalticella tirithabae (Chalcidae), Perilampus sp.
(Perilampidae) and Eurytoma sp. (Eurytomidae). Telenomus tirathabae (Scelionidae)
is an egg parasitoid. Venturia palmaris (Ichneumonidae) is a solitary parasitoid that